WASHINGTON (Reuters) - The U.S. military's top commander in the Pacific tried on Tuesday to reassure allies that Washington will maintain its commitment to Asia and maintain strong military relations with partners, some of whom are worried about President-elect Donald Trump's foreign policy.

"I have no doubt that we will continue our steadfast commitment to our allies and partners in the Indo-Asia Pacific," Admiral Harry Harris, head of the military's Pacific Command, said at an event held by the publication Defense One.

"The need for and the value of American engagement in the Indo-Asia-Pacific is convincing and it has (been) proven over decades," Harris said.

Trump suggested during the election campaign that Japan and South Korea should build their own nuclear weapons and demanded that Japan pay more for the upkeep of U.S. forces on its soil. That worries Tokyo which fears a rift in a security alliance with Washington that has been the bedrock of its defense since World War Two.

Prime Minister Shinzo Abe is expected to meet Trump in New York this week as Japan and other allies seek clarity on the direction the Republican, who has never held political office, wants to take diplomatic relations.

Harris added that he was concerned by some statements made by Philippine President Rodrigo Duterte, but that it had not had an impact on bilateral military relations.

The tough-talking Duterte has been incensed by U.S. concerns about a drugs crackdown he says is needed to save his country from ruin.

He has berated the Obama administration and made flattering comments about China but has expressed a desire to work with Trump.

Philippines Defense Secretary Delfin Lorenzana said the security alliance with the United States, including a 2014 agreement that allows prolonged deployment of American forces in the country, would not be scrapped.

However, naval exercises known as CARAT, or cooperation afloat readiness and training, and Phiblex, a marine amphibious landing exercise, would be ditched, he said. Both have been held annually.

Harris said there could be a "refocusing or maybe rescoping of some the big exercises in 2017," something he would discuss with his counterparts in the Philippines next week.

(Reporting by Idrees Ali; Editing by James Dalgleish and Alistair Bell)